I. Basic Premise of Any Air Power Use
The first and most importan t(whether its HOI2 , AOD or DH), premise in the use of air power is this: You must make air power an integrated part of your strategy. If you are using air power as just some "extra, neat thing", you're going to end up not getting nearly the full effect of air power that you can get if you work from the very beginning to make it an integral part of your strategy.
The prime reason for this is because researching air technologies, and more importantly doctrines, in a haphazard or over broad manner means that your air forces will never be fully effective. To get to the fighter doctrines, you must fully research one of the early three branches of air doctrine. If you attempt to research all three branches, your technology in other areas will be lagging far behind.
A secondary condition to this is planning your infrastructure. If you are going to be using CAS aircraft, you are going to have to build up your airfields near expected fronts for the CAS aircraft to be useful beyond the initial front early in the war. Germany, for example, must build up the Polish border provinces to house his CAS aircraft prior to Fall Weiss. Building up along the frontier of the Lowcountries and France will allow Germany to use his CAS as an integral part of his attack, shortening his battles, speeding up his conquests, and in the end reserving manpower and organization for more rapid movement around the end of the Maginot line.
On January 1, 1936, you must decide which direction you are taking your air doctrines. The two choices you have are either CAS/TAC or TAC/STR. The choice you make should be dependent wholly upon your war strategy and aims. Once you chose, IGNORE the other. Don't research CAS aircraft unless you have nothing else to do if you're going TAC/STR. On the other hand don't research and pour ICs into STR bombers if you aren't going to research the appropriate doctrines to make them effective. The reason that I say you need two of the three is that TACs are versatile enough to make up some ground on the one you don't focus on. STR and CAS combo is a long road and leaves you a big gap in effectiveness.
Two examples:
Germany: As a nation, Germany relies upon the strength of their ground forces, very specifically their armor and fast attacks, to conquer territory and integrate it quickly into their war machine to fuel further conquests. A large STR force is absolutely antithetical to this approach. Reducing infrastructure and IC of provinces you're going to conquer slows your advance and lengthens the amount of time it takes to integrate the province into your empire's production machine. The clear choice for Germany is CAS/TAC.
Great Britain: Having the sea as a wall, Great Britain is in a position that massive land combats are not to be expected. Until the aid of the United States comes into the war, you will not be able to win an extended land campaign against a Germany set to defend against it. The best defense of the Home Islands is making certain that Germany cannot mount an attack with any clear effect. Being dependent upon overseas sources for your industrial materials means that you will be vulnerable if the Germans should cut your supply lines. Large land forces garrisoning all the possible landing beaches in Great Britain can be hard on your TC, leaving your overseas holdings vulnerable to conquest. Shutting down the immediate threat of Germany is your number one goal. TAC/STR is clearly the choice for Great Britain.
II. Interceptor vs. Fighter
Interceptor
vs
Fighter
The Interceptor vs. Fighter debate is one that rages on. Many will say to go with one or the other, however, I must strongly disagree. Fighters are superior to Interceptors on offensive Air Superiority missions where the goal is to destroy the enemy fighter forces. Their much higher Air Attack value in this case is a strong point in their favor. Interceptors, on the other hand, are much better at engaging bombers than Fighters are. They have equivalent or SLIGHTLY lower attack values, but their air defense value is higher. The low air attack value of comparable tech level Escort Fighters means that the Interceptor can safely, though slowly, blast through the escort fighter then engage the bombers for maximum effect.
III. To Escort or Not To Escort, That Is the Question
Escort Fighters are ALWAYS a necessity, as you will have at least some TAC in your air force either way you go, and for these you need Escorts. STR are as much, if not more, in need of Escorts to truly do their worst against the enemy.
The Escorts will draw fire, both from enemy aircraft and enemy AA emplacements. Escorts are much hardier against these forms of attack than your bombers are. And the longer you can stay over the target, the more time you have to do the damage you wish to do.
Historically, it was determined that the most effective bomber/escort ratio was 1:1. Learn it, live it, love it. If you have 3 bombers and only one escort, as many suggest, as soon as that escort is beaten back, your bombers are in for increased losses, and lower Time on Target. If you have one Escort for each Bomber group, you will have more time over target and fewer casualties which translates into more time in the air. More time in the air means more damage.
Group your escorts with your bombers. This way you KNOW you have escort cover, and they can draw the fire.
CAG's don't operate independently of the Carrier, like in HOI1. What the CAG does to represent fighter cover is increase air defense and air attack of the carrier. Escort Fighters WILL be prioritized by the Carrier, and they will use their SURFACE defense against them, which is higher than TACs. Naval Bombers have very high (I would honestly say too high, which explains their effectiveness over TACs) surface defense ratings already. Escorts will help keep them from getting damaged, but aren't as important for NAV as they are for TAC. That being said, if Britain has Interceptors capable of covering his fleets in the North Atlantic, you might consider escorting your NAVs.
IV. Phase One of Air Operations
An Ounce of Prevention can Prevent a Pound of Pain. The first phase of effective air operations is to set up your defense against the enemy even being able to effectively enter Phase Two (Air Superiority, see next). This means getting your Interceptor umbrella set up. Combined with anti-air, a good Interceptor umbrella will help to keep your air forces in constant readiness for action as well as keep your armies fighting at full strength. When the enemy attacks, the Interceptor is the aircraft that will take down his bombers. While his fighters can be a drain on reinforcement IC, it won't be nearly as damaging as the long term effects on your IC that free ranging bombers can have.
While you cannot destroy his bomber divisions in the air, most likely, what you can do is send them home to repair and reorganize. Once you've done this, you have time to repair the damage caused by those bombers. An Interceptor screen is VITAL to any area where you have large concentrations of IC. Interceptor screens are also good to cover an advance, preventing the enemy from using his air power to hinder your movement. In short, Interceptors should be high priority from day one, and should continue to be high priority throughout the war. Unless, of course, you're the USA and don't expect many direct attacks on your airspace for a while, then you will need only set up those screens when a threat is becoming imminent.
Once the baloon goes up, get your Interceptors up and keep them up. I tend to use a group of 2 for daylight patrols in an area and a single divison for night patrols. Air cover is available 24/7.
V. Phase Two of Air Operations
The second phase of air operations is Air Superiority. Having a mission called "Air Superiority" in the game (though properly named) can be misleading. Air Superiority isn't simply in the number of aircraft you have in the air engaging the enemy. Air Superiority is removing your enemy's ability to put aircraft in the air at all. This requires a coordinated effort by your air forces to destroy not only the enemy aircraft, but also the enemy's infrastructure for those aircraft. A concerted effort of Runway Cratering and Air Superiority missions is vital to effective use of air power. TAC bombers can do this job, but not nearly as efficiently as STR bombers. That being said, TAC bombers will do just fine in Runway Cratering missions due to the multiplier on damage to runways. This is something you can, and SHOULD do, regardless of your focus.
Combining Fighter sweeps (Air Superiority) over enemy territory with Runway Cratering operations, you will quickly watch as his airforce is grounded. An airfield at 0 is going to cripple their resupply, and they don't reconstruct at amazing rates, so once his aircraft are on the ground at a beat up airfield, it will be a while before they are in the air again. Once you have this condition, you are quickly able to move to step two of the air campaign.
Once you have achieved air superiority, you can not neglect missions to maintain this condition. If you allow him to repair his airfields and reorganize his air units, you're right back to square one. Periodically hit those airfields between other attacks to keep him on the ground.
VIa. Phase Three of Air Operations (Strategic)
If you are going the Strategic route, this is when you begin to crush your enemy. Strategic Bombing and Logistical Strikes aren't effective only on production, the ramifications are felt throughout his entire army.
Your first order of business is to remove his ability to cover his IC with AA. This means bombing AA guns. This is when TAC aircraft lose their value, as the damage is lowered against these targets. Once you have removed the enemy AA in a province (or lowered it to "acceptable" levels), then you move on to the Strategic and Logistical Strikes.
When you hit IC, you aren't only lowering his production (thereby reducing his ability to resupply and reinforce his forces), you are lowering his TC, which can lower Effective Supply Efficiency, which in turn lowers overall effectiveness of his forces in the field.
When you hit infrastructure in a province before you attack it, you don't simply lower the enemy's ability to move forces in to reinforce the combat, you also lower his combat efficiency by lowering his ESE. Combined with lowered ESE from TC, you can really cripple an enemy. You MUST, however, compensate for this fact by supplying anyone who attacks this province for an offensive, as you will also be hindered by the lowered infrastructure if you don't.
On a naval note, Port Strikes with Strategic and Tactical aircraft have much the same effect on enemy naval forces as Runway Cratering missions do with his air forces. You don't need to sink his ships if they can't be repaired, refueled, and rearmed. As Great Britain, hitting German ports can be a major boon to keeping your supply lines open. Your convoys don't have to worry about submarines that are undersupplied and spending months longer in port to repair.
VIb. Phase Three of Air Operations (Tactical)
Once you have established air superiority, it is time to use your Tactical and CAS aircraft to effect. Your use of air is meant for one thing, and one thing only, winning on the ground. As such, you don't want to destroy infrastructure and ICs, you want to take them as much in tact as possible.
Ground Attack and Interdiction are your bread and butter in this case. Many would suggest using only Interdiction, as that is what lets you win battles faster by lowering enemy organization. Do not neglect Ground Attack missions, however. While Interdiction will lower the enemy organization, it does nothing to Combat Efficiency. However, each point of manpower loss is 1% lost in combat efficiency. If you hit a unit, their combat efficiency drops and their org loss will increase as a result. Org losses, however, return relatively quickly, while extra manpower losses carry over from battle to battle. In addition, a lower combat efficiency will result in less damage and org losses taken by your attacking units.
Use a combination of these attacks for greatest efficiency. I would recommend Interdiction for TACs and Ground Attacks for CAS. The increased attack values of CAS (especially when supplemented by escorting Fighters) above Basic level combines with shorter flight times and increased ground attack efficiency to make for truly staggering numbers. And once an enemy unit breaks and is on the move, Ground Attack missions from CAS aircraft will severly tear them up. Additionally, the CAS is much more effective as the war goes on and enemy Softness factors begin to drop.
One final note, Fighers have small ground attack values. If you've achieved air superiority and your fighters are sitting around doing nothing since there's no enemy aircraft to shoot at, start sending them on interdiction and ground attack missions. This lets them do something rather than nothing.
VII. Air power and the Navy
All those who poo-poo air power will quickly make an exception for naval bombers. However, TAC and STR have use in naval war as well. Aside from the above mentioned Port Strike capability, both aircraft can be used to soften up an enemy stronghold before an invasion, and can also be used to lesser effect (in the case of TAC) to aid in convoy bombing, ASW, and Naval Interdiction missions. Blasting an enemy down to 0 infrastructue on an island and grounding their naval bombers through Runway Cratering operations can be quite effective, and much more cost effective than carriers. Certainly, the carrier allows force projection of air power, but they also cost much more not only in time to build but also in all the support craft that go with them. TC and oil use wise, the air wings can be very cost effective.
The Pacific Island Hopping campaign is a perfect example of what air power in combination with the Navy can do. Little rocks in the middle of miles of ocean became strategically important because you could land airplanes on them. Midway, Guadalcanal, Iwo Jima...these historic battles occurred not because the US and Japan valued naked volcanic rocks, but because they allowed the PBYs and B-17s to fly missions closer to the next objective, and eventually against Japan itself.
VIII. Supporting the Air Force with the Army
Up until now, I've talked about the Air Forces supporting the rest of your army and navy. The Army can support the air force, as well. When you invade, make enemy airfields strategic objectives. Quickly moving and capturing an enemy airfield means you can move your CAS aircraft forward to continue supporting your advance. It can allow your TAC bombers and STR bombers to start hitting the enemy deeper inside his own territory, meaning that they cannot move their industries out of your reach. It also pushes back the area of Interceptor cover, giving your bombers a break and allowing them to continue attacks unimpeded. And it can destroy enemy aircraft if they aren't moved out fast enough.
IX. Why Go to All This Trouble?
Many people will say, "Why should I build these airplanes when I can build 3 times as many infantry with brigades?" or "Why build airplanes when I can build Tanks instead?" or "Why should I build airplanes and add in the micromanagement headache?"
The list of reasons why to chose air power over additional land power are numerous:
1) Constancy of Attack - Air power can apply pressure and damage to an enemy continuously, while land force must advance. The ability to continue to damage the enemy and keep him on his heels when he's been knocked back can mean a difference of a lot of IC and manpower spent on reinforcement.
2) Wide Ranging Effect - This applies to the Strategic strategy more so than the Tactical strategy, however it is applicable to both. The wide ranging effects of damage to IC can be devestating. 8 air divsions (4 bombers with 4 escorting fighters) hitting a province like Dresden, Cologne, or Berlin with maximum ToT can translate to big TC and production losses. TC dropping down reduces ESE of ALL of his armies. When a unit hits supply problems, they start getting a -.5% combat efficiency loss for each 1% of ESE below 100%. This can be very damaging. What other investment of IC can get a combat efficiency penalty across all units in an enemy army, navy, and air force, REGARDLESS of the size of their army (you might say "easier with a bigger army")?
3) Supply and TC efficiency - Many would say, "Why use air to weaken units on the other side of a river when I can just make an armored or Infantry corps with engineer brigades across the board?"
The answer is simple. A single group of bombers and with escorts uses 4 TC and at most (Strategic Bombers and Escort Fighters with all aircraft at Advanced level) 14 oil. IF they're flying. When idle, they use 0. They consume 10 supplies a day. And they only take 4 TC. They are much more versatile, and aren't hindered as much by bad terrain. TAC and CAS use much less of all, and the gap is much wider when you compare Basic aircraft to Basic Medium Tanks.
The Armor Corps (Advanced Med. Tanks) with Engineers uses 21 oil when on the move and fighting and 5.25 daily when idle. The only consume 8.1 supplies but cost 6 TC. They are also very one dimensional, and much less useful in bad terrain, where the aircraft are useable.
The Infantry Corps with Engineers is slower, yet more flexible, easier on Supplies, and doesn't use oil until very late in the war. However, they use the same 6 TC, and lack the ability to increase effectiveness that aircraft can lend across an entire front.
Aircraft also offer an option in oil consumption. If you start feeling an oil crunch, you can ground aircraft for a while to rebuild your strategic reserves. Armor doesn't give you this luxury. If they're deployed, they're using oil. Once you've achieved your objective, maintaining the status quo is much easier and less resource intensive. The only way to trim your oil budget with excess armor is disbanding, and this is DEFINITELY not an option you want to pursue.
4) Speed of Response - CAS and TAC aircraft can move across a continent faster than most divisions can strategically redeploy. If the enemy is making an unexpected attack, or gaining an unexpected advantage, air power is flexible enough to move to the other front and blunt the enemy assault. An armored attack can grind to a halt under heavy attack from CAS aircraft.
Sending an infantry division to reinforce a defense can take some time, especially in lower infrastructure areas (can we say Russian Steppe?). Sending in aircraft for the same purpose can take an hour or two. An hour can be all the difference in winning an losing.
X. Miscellaneous Tips for Using Air Power
A few other tips before I wrap it up:
1 - Make sure to mark any air unit messages as Show Message Popup and Pause. If you do this, you won't forget the aircraft, and once one mission is complete, you can go and examine your forces, determine their readiness, and get them back up again without missing a beat.
2 - Produce early, produce often - Air divisions are rarely destroyed (unless you let them get overrun). Produce them early and upgrade them. You can pump out infantry much faster than you can aircraft. Get your air forces up to fighting trim before you go to war, and you will have much less chance of saying, "Crud, if I had just a couple more groups, I could do this.".
3 - Continue to expand your air force as you go, planning ahead for future operations. If you want to keep England out of the war while you work on Barbarossa, keep your Luftwaffe expanding so that you can maintain the pressure on a crunched England while you deal with Stalin on the East Front.
4 - Change your focus as the need becomes apparent. If you've managed to achieve air superiority as Great Britain, when D-Day is getting closer, go ahead and start working on some CAS aircraft or increase your TAC ratio in your air force. Certainly, the CAS won't be as effective as the TAC, but they're cheap and they can make a difference on the battlefield when your enemy's advantage in technology is nullified (An ME 262 on the ground isn't going to do much against your older, slower CAS aircraft in the air).
5 - Once You Go Up, There's No Coming Down - Realize that once you commit to air power, you're going to have to intentionally lag in one area. If you're Germany or the USSR, face it, the naval war is an uphill struggle. One of the biggest mistakes, IMHO, that Hitler made was investing so much industrial manpower into the Bismark, Tirpitz, and Graf Zepelin. As Great Britain, the USA, and Japan you won't be needing advanced land forces early. Research your aircraft and navy, then stick in your land forces as you have time. Keep them, say, 1 generation behind. Or wait until you have blueprints from an Ally to speed your research before investing heavily.
6 - Night or Day Bombing? - No matter what strategy you chose, this is a choice you may want to make.
Night operations will have a penalty to attack of -80% to start and a penalty of -50% on defense.
This means that it is safer to do night missions, but less effective. The effectiveness of night missions can be increased by researching the correct air doctrines. After you've researched up to the specified Night doctrine of an aircraft, the Attack Penalty is reduced to -70%, and the defense penalty disappears.
SOME Fighter techs also lowers the night penalty for your fighters in different ways. First Strike doctrine will increase your Interceptor night air attack by +10% and your Fighters by +5% (meaning -70 or 75% instead of -80%) and Perimiter Defense Doctrine will increase your Escort's night Air Defense modifier by +50% and your Fighter's by +25% (meaning 0% for Escorts and -25% for Fighters as opposed to -50%).
ANY way you go, at a base, night attack value will be AT BEST 70% lower than day attack value. HOWEVER, if you can't really afford or don't want to build a large Escort force, night attacks are the way to go, as your defense after a little research will be at full, against an at best -70% attack of the enemy.
Of course, a night flier leader will definitely benefit in reducing these penalties. I don't know the exact modifier he gives, but 10% seems to be the norm for leader modifiers, so I would have to say that that is probably the modifier that they give.
7 - Getting aircraft where you want them - Ground Attack and Interdiction missions will be most telling in battle. The targeting AI DOES prioritize active combats as targets. However, if your air units are in the air when combat starts, they may already be targeted, or in the middle of a mission, and won't go where you need them. By the time they've returned to base and head back out again, chances are the ground combat is nearly over. Use the planning boxes to launch your aircraft one to two hours AFTER you begin a ground attack. If you win before they arrive, then the enemy will get hit on the move for big time results. If the arrive before you win, watch the little green bar shrink.
8 - Too Much of a Good Thing? - Yes, there is too much of a good thing. Use your air power in moderation. Each division above 2 in one combat gives a -2% effectiveness to ALL aircraft in the combat. If you have 30 CAS all attacking one target, you're not going to get results. Any over your command limit (minimum of 14) are going to be fighting immediately at a -25% penalty. Then everyone is going to get a -56% penalty for all those aircraft.
A good rule of thumb is to not use more aircraft in a single area than the highest level commander of all aircraft operating at the same time can command. If the highest leader you have in the area is an Air General, don't send in 5 full stacks. Send in two to one area, two to another. Of course, if you don't plan on missions overlapping, then you can excede this. For example, if you want to send a bunch of aircraft to crater the runways in Lodz, this is fine, as most of your ground attack and interdiction missions will probably go toward Poznan if that's where combat is.
9 - Be Mindful of Mother Nature - Weather can be detrimental to all military missions, but it is the one thing other than free ranging enemy bombers that can GROUND your air forces. While not paying attention to the weather with land forces means that you can expect a harder time of things, not paying attention with aircraft means MAJOR penalties. If you have storms or blizzards in the target area, aircraft cannot attack. If you have storms or blizzards over your airfield, they can't even take off. Rain and Snow can have a detrimental effect, but you can reduce this effect by researching the appropriate doctrines for the aircraft type. Attacking at night in the rain is pointless. Ground your aircraft and save the oil.
XI. Conclusion (or Yes, I'm Finally Done)
As you can see above, the uses of air power are multitudinous, and the efficiency and economy that aircraft can provide can be very useful. Not only do they provide direct benefit and the ability to do things that no other unit can do, they also multiply the force of your ground units, making your armies that much stronger across a much wider front for a much lower economic investment than just adding more ground troops can make.
While aircraft add in yet another layer of managment, once you accept this and integrate it into your strategy, you will become an even greater power than you ever could have dreamed without effective use of air power.
Feel free to add in your comments and suggestions. Any feedback is appreciated.
Very good guide.
I especially liked
the parts about integrated air power
the importance of NOT going jack of all trades but to choose wisely where to invest your resources and tech
differing and naming phases of the air war
In my experience the range of planes, especially for choosing which route to go: TAC or CAS, INT or Fighter, are extremely important dependent on what country you play, where you expect your battles and wars to take place... and kind of missing in the guide. Example: Interceptors are great but with short range and might be of not much use in many areas of the world due to distances and thus there is basically no choice but you must…
As Germany, I have a choice of lagging behind in the air or at sea, as you point out. I've always found going Fleet-in-Being with BB SAGs, if a bit gamey, gives me the power I need at sea to land my amphibious forces without a problem. That's been my workaround, but the way you laid all this out helps make the mechanics clear, if I decide to go another route! Thanks for that!